Spelunky/Headscratchers

How exactly can you wear both types of power-up shoes (and both types of power-up gloves) simultaneously?
- You got two feet, right? And two hands.
In order to take a shopkeeper's shotgun, you kill him. He is dead. Then you head to the next level, and he's guarding the exit door. Wasn't he dead a minute ago? As in, "not alive"?
- There are multiple shopkeepers. They just look alike.
- Why would any other shopkeeper want to kill you? There's no possible way they could have heard about your murderous rampage.
  - They are part of a guild of shopkeepers, and they just know.
  - If shopkeepers are currently in "shoot on sight" mode, every shop has a Wanted Poster with the Spelunker's face. Word gets around.
Why are the Damsels so grateful when you take them one level deeper into the cave? It just doesn't seem like a very helpful thing to do for a non-Spelunker in distress.
- Perhaps there's some sort of Damsel-escape route in the little passage between levels. Like a fixed teleporter linked back to the title screen or something. Unless the Damsels just hit the suicide button and get warped back out or something.